Breast cancer leads in incidence rates among all cancers in women, contributing to about one-fourth of the cancers detected. Such high incidence rates in the overall population, with nearly 1 in 8 women in the west and 1 in 11 women in India getting breast cancer sometime in their lifetime, requires intervention in terms of detection and treatment. Early detection is key to survival here as the breast cancer can be completely cured if detected in the early stages. Thermography is an emerging alternative non-radiation and non-contact screening method for breast cancer detection, whose sensitivity does not depend on the age of the woman. In the recent decade interest has been rekindled in thermography as a breast cancer screening approach with the improvement in thermal camera resolution and technology. Thermography can also be used for imaging other body parts and it accurately depicts the temperature distribution on the skin.
Malignancy increases the number of blood vessels. The experimental evidence for this dependence of malignant tumor growth and angiogenesis is known. Microcirculation is altered in cancer due to presence of nitric oxide which is released from cancerous tissue. This nitric oxide increases blood circulation creates new vessels and also recruits dormant vessels. By contact temperature measurements, it was observed that the malignant tumor is at a higher temperature than surrounding tissue. It was also observed that the malignant tumor is hotter than the temperature of blood vessels associated with the tumor. The increase in metabolic activity of the cancerous cells generates heat. This heat can be detected by a thermal camera. Malignancy also triggers regional changes to vessel shape and increases the vessel dimensions in terms of width and length compared to the normal vessels. The significant difference between the widths of normal and malignant blood vessels is due to increased blood supply. It is shown that tortuosity (twists and turns of vessel growth) is exhibited in early stages of cancer and that tumor vessels have a profound sort of tortuosity, with many smaller bends upon each larger bend. This increase in vessel caliber, vessel length, and its resultant tortuosity is also an effect of the increase in blood flow to the cancerous cells. It is important to be able to accurately isolate (extract) vessel structures in a thermographic image of breast tissue so that the tortuosity can be analyzed. The present invention is specifically directed to this effort.